I just want to know your general thoughts. Do you think we will be stuck with chemical or nuclear propulsion in space for the next 1,000 or 5,000 years? Or will we crack the gravity problem? Humanity traveling to other stars very much depends on us defying gravity.

I myself have a massive amount of research done on this topic. I'm making "steady progress" and i hope to be able to report my science findings some time in the next 12 months or so. Maybe sooner!

I just want to know your general thoughts. Do you think we will be stuck with chemical or nuclear propulsion in space for the next 1,000 or 5,000 years? Or will we crack the gravity problem? Humanity traveling to other stars very much depends on us defying gravity.

I myself have a massive amount of research done on this topic. I'm making "steady progress" and i hope to be able to report my science findings some time in the next 12 months or so. Maybe sooner!

John in Ireland.

I'm sure in time someone will figure out what a gravity wave looks like, and can replicate it - once that happens the possiblity of some sort of 'anti-gravity' will be possible.. but concidering we have no idea what a 'gravity wave' looks like, or even how to detect it.. it's going to be a LONG while.

Einstein@home is searching for gravitational waves in the data from the LIGO observatories in the USA. Since they are being upgraded to Advanced LIGO, meanwhile Einstein@home is searching for pulsars in data from Arecibo and Parkes radiotelescopes. It found two new pulsars, including a binary system in which a pulsar orbits a white dwarf. See the Einstein@home home page.
Tullio

There is no gravity to speak of in space. What I mean is that although there are gravitational effects that hold our galazy together it would still feel like Zero gravity to our space ship. We would essentially be in Zero G just like our astronauts. There is still mass however and that is what will inhibit our acceleration to near light speed. Once we have broken the bonds of earth's gravity we would be on our way. We could use the gravity of the massive planets to accelerate our space craft for a free boost in velocity.

We really don't want anti-gravity we want anti mass or anti-matter for tremendous energy propulsion from a small amount of fuel.

The problem would be to make anti-matter and then figure out how to store it and throttle it's release of energy. Probably not for a long long time.

Once we are free of the earth, accelerating at one G will give us fabulous velocity after a year or so. Figure it out: 32 feet per second each second for 365 times 24 times 3600 times 32 = about one trillion feet per second which exceeds the speed of light. Of course I have ignored relativistic effects and the cosmic speed limit. But just figure out how to achieve a constant one G acceleration and in 6 months you will be zipping right along at an appreciable portion of the speed of light. In ten years or so earth time you could be to our nearest star. Would you like to volunteer Johnny? and Tullio we could sell the book rights ahead of time maybe.

We will find gravity waves as soon as we put our interferometer out in space and give it a huge baseline. Detecting the wave will not be the same as trying to harness it. It would be like a magnet anyway; the push you would get from like poles would have to be earned by equivalent energy to place the magnets close together in the first place. If you could commutate the magnetic field then you would have something. What I mean is: let two magnets pull themselves together and then switch the field and have them repel and then figure out how to rectify this back and forth efect to provide propulsion. An electric motor sort of does this --too bad the losses in switching and magnetizing keep this from even being exactly close to unity efficiency. Electric motors can be made to be reasonably close to 100% efficient--all you need is enough copper.

"Anti-gravity" may well be possible and might even exist and be around us already. However, it certainly won't be in the usual Sci-Fi form of being switched on and off like an electromagnet. There's still the fundamental physics issue of "conservation of energy" (also known as there's no free lunch!)...

Thats true -but this is due to muscle atrophy which also weakens bones. It is a result of no gravity. We would have to create artifical gravity and also an exercise regimen with heavy resistance. Right now, we send people to live in Zero G for up to about 6 months. They have an exercise program to help defray this effect.

I would imagine that they have a higher risk of cancer due to radiation and also a risk of bone loss and osteo-porosis.

We are well adapted for our environmen,t and it would be difficult to take that environment along with us even on a trip to Mars.

I think a manned round trip to Mars should be possible in the early part of this century but interesting problems need to be solved first in terms of propulsion, cosmic rays, and health effects.

If the Large Hadron Collider can uncover the existence of the Higgs boson, which is believed to mediate gravity, this discovery may eventually have some practical effect on the control of this force. If gravity could be blocked, mass, and inertia would disappear. The light speed barrier would then seem not to apply any longer. The details of how this might work are unclear. It is not even entirely certain that the Higgs boson exists. Time will tell. Michael

The Higgs boson may not relate to gravity. The only link that I know is that it is the postulated mechanism by which Mass is experienced. Force = mass times gravity. Where gravity is the acceleration that we might experience on earth due to the warpage of space and the least energy level principle.

A Boson is a force carrier. Just as a photon is the electromagnetic force carrier. We have found the photon but it is not the necessarily the answer to interstellar engine propulsion nor of anti gravity, worm holes or anti-matter.

I am not sure if the Higgs boson really mediates gravity. That should be the task of the graviton. But the first LHC results appear to blow up supersymmetry, so every result is still pending. Incidentally, I am now crunching LHC data as an alpha tester.
Tullio

'Mediates gravity' perhaps a poor choice of words, on my part. The Higgs boson, if it exists. would apparently confer mass on matter. If matter had no mass, could it be said to be acted upon by gravity? It doesn't seem so. Perhaps it would have been better to say that the Higgs boson is an essential link in the action of gravity upon matter. Michael

Antigravity I think, exist in nature. Just not the way we humans think it does. One of the reasons I believe that, is because of a question I've wondered about for years.
What force accelerates photons to the speed of light?
Even for light, which we know is mainly photons, there has to be a point of zero speed, and an "acceleration" to light speed. Even photons can't just "suddenly" come into existance at the speed of light. Light can be produced at a milivolt, with just a mili-amp of current. So little power, yet the light produced travels at 180,000 miles per second. There's got to be some "force" that produces that acceleration from a speed of zero, to a speed of 186,000MPS. If we can identify and harness that force and use it to accelerate matter (such as a space ship) in a controlled way rapidly to near light speed, and also use that same force to counter the effects of the inertia exerted by the acceleration, then near-light speed may be possible in this century. I believe the discovery of this force will happen in my lifetime. But I will probably be dead and gone before mankind actually harnesses it.